Optoelectronic devices with organometal perovskites with mixed anions

Abstract

The invention provides an optoelectronic device comprising a mixed-anion perovskite, wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions. The invention further provides a mixed-halide perovskite of the formula (I) [A][B][X]3 wherein: [A] is at least one organic cation; [B] is at least one divalent metal cation; and [X] is said two or more different halide anions. In another aspect, the invention provides the use of a mixed-anion perovskite as a sensitizer in an optoelectronic device, wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions. The invention also provides a photosensitizing material for an optoelectronic device comprising a mixed-anion perovskite wherein the mixed-anion perovskite comprises two or more different anions selected from halide anions and chalcogenide anions.

The invention claimed is: 
     
       1. A photovoltaic device comprising:
 a first electrode; 
 a second electrode; and, disposed between the first and second electrodes: 
 a sensitizer material which is capable of performing photoinduced charge generation within the photovoltaic device, wherein the sensitizer material is a mixed-halide perovskite of the formula (I)
   [A][B][X] 3   (I)
 
 
 
       wherein:
 [A] is at least one cation, comprising at least one organic cation of the formula (R 5 R 6 N═CH—NR 7 R 8 ) + , wherein: 
 (i) R 5  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; 
 (ii) R 6  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; 
 (iii) R 7  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; and 
 (iv) R 8  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl: 
 [B] is at least one divalent metal cation, wherein [B] comprises Pb 2+ ; and 
 
       [X] is two or more different halide anions, wherein one of said two or more different halide anions is iodide, and
 a p-type layer which comprises a solid-state hole-transporting material which is not said perovskite. 
 
     
     
       2. A photovoltaic device according to  claim 1  wherein the at least one organic cation of the formula (R 5 R 6 N═CH—NR 7 R 8 ) +  is an organic cation of the formula (H 2 N═CH—NH 2 ) + . 
     
     
       3. A photovoltaic device according to  claim 1  wherein [B] is Pb 2+ . 
     
     
       4. A photovoltaic device according to  claim 1  wherein one of said two or more different halide anions is iodide and another of said two or more different halide anions is bromide. 
     
     
       5. A photovoltaic device according to  claim 1 , wherein [X] is two or three different halide anions selected from fluoride, chloride, bromide or iodide. 
     
     
       6. A photovoltaic device according to  claim 5 , wherein [X] is two different halide anions which are bromide and iodide. 
     
     
       7. A photovoltaic device according to  claim 1  wherein the perovskite is a perovskite compound of formula (IIa):
   ABX 3z X′ 3(1-z)   (IIa)
 
 wherein:
 A is an organic cation of the formula (R 5 R 6 N═CH—NR 7 R 8 ) + , wherein: 
 (i) R 5  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; 
 (ii) R 6  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; 
 (iii) R 7  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; and 
 (iv) R 8  is hydrogen, unsubstituted or substituted C 1 -C 20  alkyl, or unsubstituted or substituted aryl; 
 B is Pb 2+ ;
 X is a first halide anion wherein the first halide anion is iodide; 
 
 X′ is a second halide anion which is different from the first halide anion; and 
 z is greater than 0 and less than 1. 
 
 
     
     
       8. A photovoltaic device according to  claim 7 , wherein X is iodide and X′ is bromide. 
     
     
       9. A photovoltaic device according to  claim 7  wherein z is from 0.05 to 0.95. 
     
     
       10. A photovoltaic device according to  claim 7  wherein the organic cation has the formula (H 2 N═CH—NH 2 ) + . 
     
     
       11. A photovoltaic device according to  claim 7  wherein the perovskite has the formula (H 2 N═CH—NH 2 )PbI 3z Br 3(1-z)  wherein z is greater than 0 and less than 1. 
     
     
       12. A photovoltaic device according to  claim 11  wherein z is from 0.05 to 0.95. 
     
     
       13. A photovoltaic device according to  claim 1  wherein the solid-state hole transporting material is a polymeric or molecular hole transporter. 
     
     
       14. A photovoltaic device comprising:
 a first electrode; 
 a second electrode; and, disposed between the first and second electrodes: 
 
       (a) a p-type layer which comprises a solid-state hole transporting material, wherein the solid-state hole transporting material is a polymeric or molecular hole transporter which is not said perovskite; and 
       (b) a sensitizer material which is capable of performing photoinduced charge generation within the photovoltaic device, wherein the sensitizer material is a perovskite of the formula (I)
   [A][B][X] 3   (I)
 
 
       wherein:
 [A] is at least one cation, comprising at least one organic cation of the formula (H 2 N═CH—NH 2 ) + ; 
 [B] is at least one divalent metal cation, wherein [B] comprises Pb 2+ ; and 
 [X] is iodide, or [X] is two or more different halide anions, wherein one of said two or more different halide anions is iodide.